1. Field of the Invention
The present invention relates to a color image forming apparatus using a so-called cleaner free system for collecting toner on an image bearing member with a development device.
2. Description of the Related Art
In recent years, image forming apparatus using a cleaner free system for collecting toner on an image bearing member with a development device has attracted public attention as a means for reducing waste. According to Japanese Patent Application Laid-Open NO. 8-137174, a plurality of image forming stations using the cleaner free system are provided. In each station, a toner image formed on the image bearing member is transferred to an intermediate transfer member electrostatically by a transfer member so as to form a color image.
However, in the aforementioned image forming apparatus, “scattering of toner” and “mixture of colors”, which may cause faults in images, are in the relation of tradeoff in a relative relation between the transfer member and the image bearing member in the moving direction of an intermediate transfer member (image receiving member). The “mixture of colors” means a phenomenon that toner of another color is mixed into a development device. The “mixture of colors” is generated when a toner image transferred in an image forming station on an upstream side is transferred inversely to the image bearing member when it passes an image forming station on a downstream side. The “scattering of toner” means a phenomenon that toner is scattered around its original character proportion. If the transfer member is provided on the downstream side in the moving direction of the intermediate transfer member, the mixture of colors worsens although the “scattering of toner” is suppressed. To the contrary, if the transfer member is provided on the upstream side, the “scattering of toner” worsens although the mixture of colors is suppressed.
The image forming apparatus using the cleaner free system cannot suppress the mixture of colors and the scattering of toner.